was HYPEX amps cheap surround system

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JR.
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Re: was HYPEX amps cheap surround system

Post by JR. » Mon May 27, 2019 3:00 pm

mediatechnology wrote:
Mon May 27, 2019 10:13 am
Kinda OT WRT loss of sync/framing but...

In how many places is the Direct TV grounded?
Does it have a three wire cord?
My house does not have grounded outlets other than my DIY effort in laundry room and kitchen.
Is the dish mount or RF cable lightning arrestor bonded to a different potential?
I just walked outside to check and the satellite dish grabs a ground from the same place as the telephone and power drop is grounded. They ground the coax connector at a simple junction in the antenna wire. They did nice job with loops on either side of the junction. The original satellite dish I installed myself a couple decades ago was not as fancy (or grounded). When I put a new roof on my house, direct TV sent out a crew to move my satellite dish away from the roof surface.
Curious about where the loop current(s) are coming from.
I've never had Direct TV.
Seems like it would have both a third wire ground and a ground for the lightning arrestor.
The receiver is not grounded through a line cord but likely to the satellite dish through the coax antenna cable. It may not even be a simple ground loop. I think there is a separate lump powering the antenna front end. Since my hypex is not grounded I don't see what a loop could be between.

That said my first pass system grounding scheme is mostly floating with the digital decoder powered by its own wallwart and its single ended outputs feeding the hypex differential inputs. So no low Z bond between decoder chassis and hypex ground (probably a small RF cap inside the hypex from inputs to ground, but I haven't seen a published schematic for that.)

I haven't advanced this project further, because it worked so well from the very first power up, and is dead silent using optical for the digital program material.

Since I had the same digital funny business with two different cheap decoders and also different power amps, I am almost tempted to try a new optical cable, but that seems extremely low probability. :roll:

I suspect i could get the coax input quiet with better hypex grounding scheme (maybe even power the digital decoder from the hypex 5v rail which would automatically ground it). But not today, did I mention it really sounds good.

Since it went over 10 days last time without a hiccup, this is not a huge inconvenience. I still haven't found a "better" digital surround decoder for less than 10x-20x cost.

JR

PS: My reluctance to put this back on the bench for tweaking is unhooking all the speaker wires... then reconnecting them. :roll: I should maybe buy some banana plugs. :lol:
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Re: was HYPEX amps cheap surround system

Post by mediatechnology » Mon May 27, 2019 3:09 pm

I'm wondering if the Direct TV receiver isn't corrupting itself.
What happens if you don't change the decoder and power cycle the DTV box?
https://ka-electronics.com

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Re: was HYPEX amps cheap surround system

Post by JR. » Mon May 27, 2019 5:14 pm

mediatechnology wrote:
Mon May 27, 2019 3:09 pm
I'm wondering if the Direct TV receiver isn't corrupting itself.
it could be complicit... I am pretty sure the screw up is local inside the digital 5.1 decoder.

I have not confirmed this but could unmute the sound in the TV monitor (fed by HDMI) but i suspect it is still clean... I have never heard it get squirrelly, just the 5.1 outputs. I have to keep the monitor muted because there is a several tenths of a second delay. The new digital decoder has a noticeably longer delay than the early one, but that old one still caused comb filtering.
What happens if you don't change the decoder and power cycle the DTV box?
I haven't tried that specifically but I suspect it could reset the screwed up digital decoder. I can also reset the decoder by switching between 5.1 mode and 2.1 mode, then back again, or switching to coax and back. So apparently any reset of the digital decoder clears it up.

It supports numerous formats so the algorithm that selects what format it is working in loses itself. At one point I thought it was playing 2.1 but it isn't. Recognizable program but lower level and distorted, with nothing in center (vocal) channel.

I think I have tried changing the channel and that didn't work, so direct TV must be constantly sending out a data stream. The Bangalore reset works. Turning off the direct TV and on again, could be done from my easy chair :lol: but I need the exercise.

JR

[edit- turned on the surround system first thing this morning to try to catch it misbehaving, even though I am just watching business news. FWIW the commercials are far more annoying in full fidelity bandwidth. :roll: [/edit]
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Re: was HYPEX amps cheap surround system

Post by mediatechnology » Thu May 30, 2019 6:51 am

Maybe you'd be better off just turning off the TV permanently.
If I lived alone I'd only turn it on if there were a tornado heading my way.
https://ka-electronics.com

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Re: was HYPEX amps cheap surround system

Post by JR. » Thu May 30, 2019 7:47 am

mediatechnology wrote:
Thu May 30, 2019 6:51 am
Maybe you'd be better off just turning off the TV permanently.
If I lived alone I'd only turn it on if there were a tornado heading my way.
Be my guest... :lol:

With my new improved surround system I am hearing sound effects in movies I didn't hear before, mainly very LF. A known flaw in my original 5.1 decoder was that the sub output was around 10 dB low. Yesterday was too much political drama to listen to the news harpies, so I listened to one of the direct TV jazz channels. Again the improved sound was a noticeable improvement.

---

I ordered some speaker banana plugs to overcome my reluctance to disconnect and reconnect 12 speaker wires. :lol:

JIC I ordered a new optical cable while I consider that a very low likelihood to be responsible. There were phoolish versions of optical cables with gold plated ends. :roll:

JR
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Re: was HYPEX amps cheap surround system

Post by JR. » Sun Jun 02, 2019 3:07 pm

It took a while but the watched pot finally boiled again so I was able to test the "Bangalore" reset on the Direct TV receiver digital source.

I was surprised because I expected it to work but no bueno... powering down and up again, did not clear the digital decoder mis-sync.

The bangalore reset did work on the digital decoder.

JR
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Re: was HYPEX amps cheap surround system

Post by mediatechnology » Sun Jun 02, 2019 4:03 pm

Yesterday was too much political drama to listen to the news harpies, so I listened to one of the direct TV jazz channels.
Ahh, much better.

My wife likes to watch the PBS cooking shows on Saturday.
Sometime after "This Old House" I hear the sounder for the "News Hour" and I have to make a mad rush for the off button, mute, or change channels.
It will rot your mind.

Sounds like your decoders share a common code base as you thought.
https://ka-electronics.com

Meme World https://www.memeworld.com/
Project Veritas: Google "Machine Learning Fairness" Whistleblower Goes Public, says: "burden lifted off of my soul." https://www.youtube.com/watch?v=g1VeElB ... e=youtu.be
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Re: was HYPEX amps cheap surround system

Post by JR. » Sun Jun 02, 2019 6:09 pm

mediatechnology wrote:
Sun Jun 02, 2019 4:03 pm
Yesterday was too much political drama to listen to the news harpies, so I listened to one of the direct TV jazz channels.
Ahh, much better.

My wife likes to watch the PBS cooking shows on Saturday.
Sometime after "This Old House" I hear the sounder for the "News Hour" and I have to make a mad rush for the off button, mute, or change channels.
It will rot your mind.

Sounds like your decoders share a common code base as you thought.
well the second generation got better and a little cheaper so I wonder what comes next. :lol:

JR
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Re: was HYPEX amps cheap surround system

Post by JR. » Sun Jun 02, 2019 8:22 pm

Just to confirm what was going on, I turned off the direct TV receiver with the remote control and pulled the optical cable... it was still glowing red, which tells me the digital carrier is still coming from the receiver even when receiver is nominally turned off.

To remove power completely from the receiver and re-powering it up causes it to reboot which takes several minutes to download new operating system from the satellite so not practical.

Next time it gets funny, I can try unplugging and replugging the optical cable. That might work, but I am no longer making predictions. :lol:

JR
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Re: was HYPEX amps cheap surround system

Post by JR. » Wed Jun 05, 2019 8:41 am

My new optical cable arrived but I waited for the decoder to lose it's place again so I could perform the experiment of removing and restoring the optical signal to see it that resets it... it didn't. So when the digital decoder heads south (why do they call bad stuff heading south?) the only way to fix it is resetting the decoder... either by changing front panel switches or using the Bangalore reset (removing and restoring power).

Today I will replace the optical cable and wait to see if that makes a difference. I consider the optical cable a low probability as a cause.

When the decoder gets tangled up, it still makes recognizable sound clearly decoded from source that is playing but center channel is much quieter and other channels not correct.

JR
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

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